@truthfinder: You were walking on the treadmill while writing your post and the Fitbit on your wrist. So your arm was not moving/swinging with every step you were taking ? And you expect the Fitbit to record your step without your arm swinging ? What nonsense is that ? The Fitbit and every other similar arm/wrist band pedometer that pretends to count your step while sitting on your arm is making fools of consumers like you. And once the step count is wrong, every other information such an instrument gives out is wrong. Did this never occur to you?

I don't know where to start. I certainly don't appreciate your tone. Did I say the Fitbit was on my wrist? (No) Do I look like an idiot? (Don't answer that :-)

As an engineer (I R an engineer), these questions/points certainly did occur to me. But rather than me taking the time to answer you here, may I suggest that you read the follow-up blog I will be posting later today that actually addresses all of the questions you raise.

I hope you are having a happier day than the tone of your comment would suggest :-)

You were walking on the treadmill while writing your post and the Fitbit on your wrist. So your arm was not moving/swinging with every step you were taking ? And you expect the Fitbit to record your step without your arm swinging ? What nonsense is that ? The Fitbit and every other similar arm/wrist band pedometer that pretends to count your step while sitting on your arm is making fools of consumers like you. And once the step count is wrong, every other information such an instrument gives out is wrong. Did this never occur to you ?

I think it was just a small tie-in that that the 24F is suitable for low-power applications -- and they wanted to give a gift that reflected this -- just something showing an example of a low-power application even if it didn't contain their procerssor.

Whatever ... I'm, walking on my desk treadmill as i pen these words -- and the think that's motivating me to do so is the Fitbit :-)

@Max: I'd been doing a bit of research by my own about which processor powers the Fitbit devices after the APP chat -- I was interested in how they were able to perform such a smart DSP algorithm.

I found some teardowns pointing that at least the Fitbit Zip and One were powered by an ST's Cortex-M3 powered SoC -- 32bits arithmetics was the answer for the processing capabilities of those little scamps!!

But if so... what's the point with the PIC24F? Maybe Fitbit has done a quiet product upgrade/revision?

Max, a great, informative writeup but you forgot the part about sharing your results with your friends and family and having it become so visciously competitive that you want to divorce them all! Also, one tiny glitch: The device does not compensate for different time zones, my husband was in Colorado yesterday and his workout at the end of the day rolled over to today, much to his chagrin!!!